Drilling rig safety brake



June l1, 1957 w. B. DRIVER DRILLING RIG SAFETY .BRAKE 2 Sheets-Sheet 1Filed April 26. 1954 QINIVENTOR.V

A 7' TORNE.

. .im 11', '1957 w; B. DRIVER 2,795,301

DRILLING RIG SAFETY gAxE 2 sheets-snelst g Filed April 26, 1954 A TTRNEY masser nanars@ nro sanary naar@ William E., Driver, Wynnewood,

Application April 26, 1954, Serial No. 425,633

2 Claims. (Cl. 18S- 189) The present invention relates to the oil welldrilling industry and more particularly to a safety device for actuatingthe brake control lever on a rotary drilling rig upon the failure of theautomatic-driller.

A number of the recently developed rotary drilling rigs have beenequipped with a control unit which is known in oil eld parlance as anautomatic-driller, as above referred to. This device lis locatedadjacent the position the driller usually stands while operating the rigand has operative connections with the controls of the drilling rig,which are usually actuated by hydraulic oil pressure from a pump drivenby the source of power for the drilling rig. rllhis automatic-driller isused for maintaining a constant rate of feeding the drill pipe intothe'hole or to regulate the penetration of the drill bit by the -amountof weight of `the drill pipe. By using thisk automatic-driller linconnection with a drilling rig itis not necessary that the drillelremain at his post all the time; thus allowing him more freedom duringthe time it takes for the Kelly-joint to go downward through the rotarytable. However one fault of the automaticdriller is that the pressurelluid pump is chain driven and when this chain breaks, as happensoccasionally, the controls of the automatic-driller are then releasedand the weight of the traveling blocks, swivel and rotary hose unwindsthe drilling cable olf of the drilling rig drum shaft and all of theabove named equipment falls on the derrick floor. The drilling rig keepsturning the Kellyjoint and considerable damage to the drilling equipmentresults, which may easily run into the thousands of dollars to repair.or replace damaged or broken parts.

It is upon such a drilling rig, equipped with an automatic-driller thatthe device of the present inven- -tion is designed to be installed toactuate the brake control lever upon the failure of theautomatic-driller. The invention accomplishes this by a governoractuated valve axially mounted to a small wheel, rotatably contactingthe periphery of one of the rnain brake drums of the drilling rig. Uponfailure of the automaticdriller the rapid rotation of the brake drumspins the small wheel opening the governor actuated valve admittingpressure to a hydraulic cylinder operatively connected to the brakecontrol lever which stops the rotation of the brake drum and the drawworks.

Accordingly it is the principal object of ythis invention to provide asafety device for stopping the unwinding of the drilling line from thedrum shaft of a rotary drilling rig equipped with an automatic-drillerby actuating the brake control lever.

Another object is to provide a safety device of this class which may beadapted for use in connection with any type of rotary drilling rig.

Still another object of this invention is to Aprovide a safety devicethat is comparatively cheap to manufacture.

Yet another object of this invention is to provide a device that iscompletely automatic in its operation.

A further object of this invention is yto provide a device which may beeasily disconnected from the drilling rig when its use is not desired.

Other objects will be apparent from the following description when takenin conjunction with the accompanying two sheets of drawings, wherein:

Figure l is a fragmentary elevational end view of the draw works of arotary drilling rig with the device installed thereon;

Figure 2 is an elevational side view of the device, similar to Figure 1,but on a larger scale 1to more clearly show the details thereof;

Figure 3 is a perspective view of the device per se; and,

Figure 4 is-a fragmentary elevational view partly in section, showingthe details of a portion of the device.

Like characters of reference designate like parts in those figures ofthe drawings in which Ithey occur.

In the drawings: p

The reference numeral 1 indicates, as a whole, the drillers end of thedraw works of a `conventional rotary drilling rig.

The reference numeral 2 indicates the main drum at the drillers end ofthe drum shaft having a-b'rake band therearound, not shown, which is`operatively connected to and actuated by a brake control lever 3.

Referring more particularlytolFigure 3,`the reference numeral 16indicates the device, as a whole, comprising, a `rectangular base plate11 having an upper surface 9 and a pair of rigid longitudinallyextending arms 12 at one-end. To the outermost end of each arm12,'respectively, is pivot-ally attachedby bolts and nuts 13 a pair ofelongated upstanding strap metal brackets 14, of a selected length,havingtheir upper ends 17'turned 4at right angles and rigidly connectedto a suitable beam 15 of the rig bylbolts and nuts 16 (Figs. l and 2).To the opposite end of the plate 11 is rigidly attached, preferably asby welding, a pair of spaced-apart depending longitudinallyextendingalignedly perforated lugs 2t). A rod 21, substantially the same lengthas the spacing .of the lugs 2li, has its respective ends pivotallydisposed axially within the aligned perforations of the lugs 20, as at22. To one side of the rod 21 adjacent each lug is rigidly attached apair of parallel bolts 23, perpendicular to the rod 21. A pair ofvertically disposed strap iron brackets 24 each have their respectiveend portions 25 and 26' formed in right angle co-operative parallelrelation forming a U-shape. T'he depending leg end portions 26 arethrough-perforated to loosely receive the bolts 23, respectively, andare held in slidable relation therearound by nuts 27. The upper leg ends25 are through perforated for connection with the support 15 by boltsand nuts 2S. A metal disc or washer 30 is rigidly connected axially toeach bolt 23, respectively, at a selected point spaced from the bracketend 26.V A helically wound compression spring 31 is axially disposedaround each bolt 23, respectively, between the disc 30 and the bracketend 26 for the purposes more fully explained hereinbelow.

A shaft 35 of a selected diameterand having a length slightly greaterthan the width of the plate 11 is rotatably mounted transversely to theupper surface 9 of the-plate ll'nby rigidly connected suitable bearings36. A wheel 38, of a selected diameter, is rigidly mounted axially too-ne 'end of the shaft 3S in face to face alignment with the brake drum2 and with a portion of the-periphery of the wheel 38 contacting'` aportionof the periphery of the drum 2. On drilling rigs which haveaprotective housing over the brake drum 2, it may be necessary toplained hereinbelow. To the opposite end of the shaft 35 is rigidlyconnected an inertia type governor 40, comprising, an elongatedthrough-perforated rectangular base bar 43 rigidly connectedperpendicularly to the shaft 35 through the perforation by ya suitablekey, not shown, and is held thereon by the washer 41 and the nut 42. Theends of the base 43 are vertically slotted to pivotally receive onpivot, pins 46 the ends of a pair of oppositely disposed governor arms44, each having an enlarged outer end portion 45 (Fig. 4). The arms 44are held in idle or collapsed position as shown by the solid lines ofFig. 4, by a suitable tension spring 47 connected to each arm 44 and theadjacent side of the washer 41, respectively. Upon the rapid rotation ofthe shaft 35 by the wheel 38, centrifugal force urges the governor arms44 to pivot outwardly from the shaft toward the position, as shown indotted lines (Figs. 3 and 4), for

purposes more fully explained hereinbelow.

A ,conventional quick opening valve-cock 50 having a laterally extendingthrottle arm 51, slanted downwardly at its free end, as at 52, isthreadedly engaged between the ends 53 and 54, respectively, of ahydraulic pressure supply line connected to a hydraulic pump, not shown,of the drilling rig 1. The valve-cock 50 is held in spaced parallelrelation above the upper surface 9 of the plate 11 with the throttle armspaced above the governor 40, by a pair of upstanding suitable splitclamps 55 rigidly connected at one end of the` upper surface 9 of theplate 11 and grippingthe lines 53 and 54,'respectively.

A conventional hydraulic cylinder 60 is pivotally connected at its baseend 64 to the beam 15 by a pivot pin 61. The piston end 62 of thecylinder 60 is pivotally connected by a pivot pin 63 to the brakecontrol lever 3 adjacent its free end (Fig. l). The line 54 is connected to the cylinder 60 in a conventional manner. Whenever` the drum 2starts to unwind the drilling line, not shown, by rotation in thedirection of the arrow (Fig. l) due to some mechanical failure of theconventional equipment, the drum 2, being substantially largercircumferentially than the wheel 38, rotates the wheel 38 and shaft 35very rapidly which actuates the governor 40 by centrifugal force. Theenlarged ends 45 of the governor arms 44 being pivoted outwardly by thiscentrifugal force, contact the downward extension S2 of the throttlelever 51 to open the valvecock 50. Hydraulic pressure then flows throughthe line 54 and actuates the cylinder 60 which depresses the brake control lever and stops the rotation of the drum 2. Normally the functionof the springs 31 is to urge the plate 11 downwardly to keep the wheel38 in frictional engagement with the periphery of the drum 2 at alltimes. Whenever it is desired to operate the drilling rig without theuse of the safety brake 10, the following mechanism is provided. A link65 of a selected length, is pivotally connected at one end between apair of upstanding ears 66 rigidly connected to the upper surface 9 ofthe plate 11 adjacent one end 26 of a bracket 24. The free end of thelink 65 is provided with a laterally extending hook portion 67 adaptedfor contaction with the upper surface of the end 26 `of the bracket 24.The plate 11 is manually pivoted upwardly around the bolts 13,compressing the springs 31 which raises the wheel 38 from Contact withthe drum 2, as shown by dotted lines Fig. 2, and the link 65 is pivotedupwardly placing the hook portion 67 over the end 26, as shown in dottedlines, Fig. 2. The link 65 then holds the device 10 in an inoperativeposition until the link 65 is again released.

Operation The device is installed on a drilling rig in the mannerdescribed herein above, and is to be used with an automatic drillingcontrol. If at any time the drilling control mechanism fails, whichallows the drilling cable to unwind oit of the cable drum shaft, thedrum 2 rotates the wheel 38 and causes the governor 40 to open thevalve-cock 50 which actuates the hydraulic cylinder 60 by hydraulicfluid pressure to depress the brake control lever 3 which stops therotation of the drum 2 and prevents damage to the drilling equipment.When it is desired to use the drilling rig without the device 10 beingconnected, it may be disengaged from contact with the drum 2 asdescribed hereinabove, and the hydraulic cylinder pivot pin 63 removed,thus allowing conventional operation of the drilling rig 1.

Obviously the invention is susceptible to some change or alterationwithout defeating its practicability, and I therefore do not wish to beconfined to the preferred embodiment shown in the drawings and describedherein, further than I am limited by the scope of the appended claims.

I claim:

1. A safety brake for a rotary drilling rig having a rotating brake drumand having a brake control lever, including: a substantiallyhorizontally disposed rectangular plate pivotally mounted at one end onsaid rig adjacent the periphery of said brake drum; a pair ofsubstantially U-shaped brackets each rigidly connected in dependingrelation by one leg of the U-shape to said rig above the free end ofsaid plate disposing the depending leg of said bracket in spacedparallel relation above the free end oi said plate, the depending leg ofeach said bracket having a perforation intermediate its ends; a pair ofbolts pivotally connected at one end to the free end of said plate, saidbolts slidably connected to the respective depending legs of saidbrackets through said perforations for permitting vertical movement ofthe free end of said plate toward and away from said brackets; a helicalspring axially disposed around each said bolt for normally urging thefree end of said plate away from said brackets; a shaft rotatablycarried transversely by the upper surface of said plate in axialparallel relation with said drum, the length of said shaft being greaterthan the width of said plate; a wheel axially mounted on one end of saidshaft in rotatable peripherial contact with said brake drum; an inertiagovernor axially carried by the end of said shaft opposite said wheel; ahydraulic cylinder pivotally connected at each end to said rig and saidbrake control lever, respectively, said cylinder having a hydraulicsupply line extending longitudinally across said plate; a .Pair ofclamps rigidly carried in longitudinal spacedapart relation by the uppersurface of said plate for holding said supply line in spaced parallelrelation above said plate; and a quick-opening valve in said supply linebetween said clamps, said valve having a laterally extending handlenormally projecting toward the extended rotating path of said governorwhen said valve is in closed position, whereby rapid rotation of saidbrake drum revolving said wheel actuates said governor for contactingand moving said valve handle to open position for actuating saidcylinder and depressing said brake lever thereby stopping the rotationof said brake drum.

2. Structure as specified in claim l and a latch pivotally connected atone end to the upper surface of said plate adjacent the depending leg ofone said U-shaped bracket, said latch having a hook-shaped free end forengagement with the upper surface of the depending leg disposing theperiphery of said wheel in spaced-apart relation with said brake drumfor inactivating said safety brake.

References Cited in the le of this patent UNITED STATES PATENTS 705,623Stevens `Tuly 29, 1902 785,817 Mason Mar. 28, 1905 950,477 Courtois Mar.l, 1910 1,634,565 Wallbillich July 5, 1927

